Sunlite Alloy Seatpost Shim 27.2id to 30.9odThis is Sunlite’s Seatpost Shim that converts seat posts with 27.2id measurements to fit with 30.9od components. The long design allows for extra support to make the conversion solid. Also with a lip to make sure your components stay where you place them perfectly. Composed of Alloy, weighs only 38g!072774516964